Using a newly developed long-period grating filter to improve the timing tolerance of a 320 Gb/s demultiplexer

A 0.8 ps flat top pulse is generated using a long-period fibre grating and used as control pulse for the first time in a 320 Gb/s demultiplexer. The effect is an increased error-free timing tolerance.</p

Mastocytosis: a Rare Case of Anaphylaxis in Paediatric Age and Literature Review

The term “mastocytosis” denotes a heterogeneous group of disorders characterised by abnormal growth and accumulation of mast cells (MC) in one or more organ systems. Symptoms result from MC chemical mediator’s release, pathologic infiltration of neoplastic MC in tissues or both. Multiple molecular, genetic and chromosomal defects seem to contribute to an autonomous growth, but somatic c-kit D816V mutation is more frequently encountered, especially in systemic disease. We present a literature review of mastocytosis and a rare case report of an 18 month-old-girl with a bullous dermatosis, respiratory distress and anaphylaxis, as clinical manifestations of mastocytosis. The developments of accepted classification systems and novel useful markers allowed a re-evaluation and updating of the classification of mastocytosis. In paediatric age cutaneous forms of disease prevail and may regress spontaneously. SM is more frequently diagnosed in adults and is a persistent(clonal) disease of bone marrow. The clinical course in these patients is variable.Today diagnostic criteria for each disease variant are reasonably well defined. There are, however, peculiarities, namely in paediatric age, that makes the diagnostic approach difficult. Systemic disease may pose differential diagnostic problems resulting from multiple organ systems involvement. Coversly, the “unexplained” appearance of those symptoms with no skin lesions should raise the suspicion of MC disease. This case is reported in order to stress the clinical severity and difficult diagnostic approach that paediatric mastocytosis may assume

Arbitrary-order ultrabroadband all-optical differentiators based on fiber bragg gratings

We introduce a general approach for designing ultrabroadband arbitrary-order all-optical (all-fiber) time differentiators based on the use of fiber Bragg gratings (FBGs). Specifically, we numerically demonstrate that an Nth-order time differentiator can be implemented using a single specially apodized highly dispersive linearly chirped FBG operated in transmission. A concatenated reflection phase-shifted FBG is also required for implementing any odd-order differentiator. Our numerical simulations show that accurate and efficient time differentiation of optical signals with bandwidths up to a few hundreds of gigahertz can be realized using readily feasible FBG structures

Novel modal delay measurement for higher-order mode fiber using stretched pulse - based interferometry

We propose a novel modal delay measurement technique for higher-order mode fiber based on real-time optical frequency-domain reflectometry (OFDR) using an extremely simple, entirely passive and ultrafast wavelength sweeping mechanism, namely dispersion-induced optical pulse stretching